RESUMO
Cercophorins A-C (3-5), three novel isocoumarin derivatives with antifungal and cytotoxic activities, have been isolated from the coprophilous fungus Cercophora areolata (JS 166 = UAMH 7495), a colonist of porcupine dung. Two additional new isocoumarins, decarboxy-citrinone (1) and 4-acetyl-8-hydroxy-6-methoxy-5-methylisocoumarin (2), and a known tricothecene mycotoxin, roridin E (6), were also obtained from this species. Compounds 1-6 were isolated from ethyl acetate extracts of mycelia and liquid cultures of C. areolata through bioassay-guided fractionation and are the first metabolites to be reported from a member of the genus Cercophora. Their structures were assigned on the basis of MS, selective INEPT, and 2D-NMR experiments.
Assuntos
Antifúngicos/isolamento & purificação , Ascomicetos/química , Cumarínicos/isolamento & purificação , Antifúngicos/química , Ascomicetos/efeitos dos fármacos , Ascomicetos/metabolismo , Bacillus subtilis/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Cumarínicos/química , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Espectrometria de Massas de Bombardeamento Rápido de Átomos , Staphylococcus aureus/efeitos dos fármacos , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
Sclerotiamide (1), a new fungal natural product related to the paraherquamides, was isolated by bioassay-guided fractionation of antiinsectan organic extracts from the sclerotia of Aspergillus sclerotiorum (NRRL 5167). The structure was determined primarily through 1H-NMR, 13C-NMR, HMQC, and HMBC experiments. Sclerotiamide causes significant mortality and unusual physiological effects in dietary assays against the corn earworm Helicoverpa zea.
Assuntos
Aspergillus/química , Besouros/fisiologia , Indolizinas/isolamento & purificação , Inseticidas/isolamento & purificação , Compostos de Espiro/isolamento & purificação , Animais , Cristalografia por Raios X , Depressão Química , Ensaios de Seleção de Medicamentos Antitumorais , Comportamento Alimentar/efeitos dos fármacos , Indolizinas/farmacologia , Inseticidas/farmacologia , Larva , Espectroscopia de Ressonância Magnética , Espectrometria de Massas de Bombardeamento Rápido de Átomos , Compostos de Espiro/farmacologiaRESUMO
Scleramide (1), a new cyclic hexapeptide, and a new oxidized bisindolyl benzenoid derivative (2' '-oxoasterriquinol D methyl ether, 2) were isolated from extracts of the sclerotia of Aspergillus sclerotiorum (NRRL 5167). The structures of these compounds were determined by analysis of 1D and 2D NMR experiments.